The evaluation of usefulness of the newly manufactured immobilization device

To evaluate the usefulness of the handmade patient immobilization device and to report the clinical results of it. We made two fusion images and analyzed those images. One image is made with diagnostic MR image and CT image, the other with therapeutic planning MR image and CT image. With open head holder, we measured the skin dose and attenuation dose. Also, we made the planning CT couch plate with acrylic plate and styrofoam and compared artifact. We could get more accurate fusion image when we use MR head holder(within 2 mm error). The skin dose was reduced 2 times and the attenuation dose was reduced more than 20% when open head holder used. The planning CT couch plate was more convenient than conventional board and reduced artifact remarkably. We could verify the localization point in the MR image which is taken with MR head holder. So we could fuse the image more accurately. The same method could be applied to PET and US image, if the alike immobilization device used. With open head holder, the skin dose and the attenuation dose was reduced. And those above devices could substitute for expensive foreign device, if those are manufactured adequately.